Device for two-dimensional application of free-flowing adhesive to strip material

ABSTRACT

A device for the two-dimensional application of free-flowing adhesive to strip material, especially to furniture edge banding. An adhesive channel is contained in an applicator head and an applicator valve selectively blocks or releases the flow of adhesive in the adhesive channel. A slot nozzle communicates with the adhesive channel, which nozzle has a slot-shaped exit opening for dispensing adhesive onto the strip material. A guide device for guiding the strip material past the exit opening of the slot nozzle along a defined path is removably attached to the applicator head. The guide device includes a first guide element which comes in contact during operation with the surface of the strip material opposite the surface to be glued, and at least one additional guide element which comes in contact during operation with an edge of the strip material.

This application claims the priority of German Patent Application No.10051201.1 filed Oct. 16, 2000, the disclosure of which is hereby fullyincorporated by reference herein.

FIELD OF THE INVENTION

The present invention pertains to a device for the two-dimensionalapplication of free-flowing adhesive to a strip material, especiallyfurniture edge banding, which is in motion relative to the device.

BACKGROUND OF THE INVENTION

Devices of this type are used to apply adhesives two-dimensionally tofurniture parts or strip-like substrates. The applicator head is usuallymounted on a frame, and the strip material is conveyed past theapplicator head by a transport device. During operation, the adhesiveemerges from the elongated exit opening of the slot of the slot nozzleassembly and is dispensed onto the surface of the substrate beingconveyed past the exit opening. The elongated exit opening of the slotis usually oriented crosswise or transverse to the direction of therelative motion between the applicator head and the substrate.

When so-called edge banding is glued to the edges of furniture, theprocedure used so far according to the state of the art is to apply glueto the edge of a furniture part and then to press the edge banding,which is a flexible material strip of plastic, onto the previously gluededge of the furniture part. The glue is applied to the furniture parteither by hand with considerable effort or with the help of automaticdevices, which apply the adhesive by machine to the furniture parts. Inboth cases, considerable expense is involved.

SUMMARY OF THE INVENTION

The task of the present invention is to provide an application deviceand a guide device suitable for applying an adhesive directly to stripmaterial or the like. In particular, an application device of thisinvention easily and precisely applies edge banding, molding, or thelike keep parts or other workpieces.

According to the invention, a guide device guides the strip materialpast the exit opening of a slot nozzle along a defined path. The guidedevice includes a first guide element, which comes in contact duringoperation with the surface of the strip material opposite the surface tobe glued, and at least one additional guide element, which comes incontact during operation with an edge of the strip material. The guidedevice is preferably attached in a removable manner to an applicatorhead having the slot nozzle.

With a simple design, the invention makes it possible to apply adhesiveprecisely and reliably in two dimensions to strip material, edge bandingfor furniture parts, molding strips, etc. The guide device according tothe invention has a first guide element which ensures that the stripmaterial to be glued is conducted past the exit opening of the slotnozzle either at an adjustable distance or in actual contact with theslot nozzle, so that the free-flowing adhesive is applied reliably anduniformly to the surface of the strip material to be glued. According tothe invention, furthermore, the gluing as such and its quality can beinfluenced by adjusting the distance between the guide element and theexit opening, as a result of which the thickness of the applied glue canbe controlled. Using at least one additional guide element, the stripmaterial to be glued is also guided laterally along the desired path, toachieve the optimum orientation of the strip material to be gluedrelative to the exit opening of the slot nozzle. Through the attachmentof the guide device directly to the applicator head, complicated supportstructures can be eliminated, and the guide device can be easilyretrofitted to existing applicator heads. If an applicator head is alsoused for a different purpose which does not require the guidance of astrip-like substrate, the guide device can be easily removed from theapplicator head. After the application of the adhesive to the stripmaterial, the material can be bonded to other workpieces; for example,edge banding can be glued to furniture parts.

In a preferred embodiment of the invention, it is proposed that theguide device is supported by a swivel joint on the applicator head. As aresult of this swiveling support, the guide device can move easily byvirtue of its design so that, first, it can be adjusted to accommodatestrip material of different thicknesses and, second, so that the firstguide element can be moved between a contact position, in which thestrip material to be glued is pressed against the nozzle assembly tocreate contact with the surface to be glued, and a rest position. Inthis latter position, production may be interrupted or gluing may bestopped, and the guide element makes no contact with either the slotnozzle or with the strip material.

According to a further aspect of this embodiment, the guide device maybeswiveled by a pneumatic cylinder. The first guide element is mounted atsuch as a distance from the swivel joint that, when the guide device isswiveled, the distance between the first guide element and the exitopening of the slot nozzle changes. In this way, the movement betweenthe working position and the rest position can be easily produced.

Another embodiment is characterized by a preloading device to exert apreloading force on the guide device and/or the guide element toward arest position, in which the guide element is held a certain distanceaway from the slot nozzle. The preloading device is preferably designedas a spring. As a result, in the case of an unwanted interruption in theoperation (e.g. emergency shutdown), the strip material to be glued willnot be pressed against the slot nozzle, which may be heated. Instead,the guide element will be swiveled into a rest position a certaindistance away from the exit opening of the slot nozzle.

In a variant of the guide device according to the invention, it isprovided that the first guide element is designed as a cylindrical bolt,which is set up essentially parallel to the exit opening. Suchcylindrical bolts are easy to manufacture and provide reliable guidancewith little friction. As alternatives, the first guide element couldalso be designed as a plate or as a rotating roll.

In another embodiment, it is proposed that two additional edge-guideelements be attachable to a support at variable distances from eachother. These two edge-guide elements guide the substrate on both sidesso that no unwanted shifting relative to the elongated exit opening ofthe slot can occur. Because the distances between the two elements isvariable, it is also possible to adapt the guide to strip material orsubstrates of different widths.

It is also preferred that the support be mounted so that its position,along with that of the edge-guide elements, can be adjusted and thenfixed in place on the guide device. This allows the two edge-guideelements to be aligned jointly relative to the strip material.

In another embodiment, the guide device is provided with a guide slotformed by plates a certain distance apart. The substrate or stripmaterial is conveyed through this guide slot. With the help of thisguide slot, it is possible to process, in particular, strip materialswhich have already been cut into sections. Such sections of material arefed reliably through the guide slot to the slot nozzle, even if thematerial is flexible or has the tendency to bunch up, as can be the casewith edge banding.

BRIEF DESCRIPTION OF THE DRAWINGS

Various additional features, objects and advantages will be readilyrecognized upon further review of the exemplary embodiments. Theinvention is described below on the basis of the exemplary embodimentswith reference to the attached drawings:

FIG. 1 is a perspective view of a device according to the invention forapplying adhesive;

FIG. 2 is a perspective view of a guide device according to theinvention;

FIG. 3 is a side view of the applicator device according to FIG. 1 witha mounted guide device according to FIG. 2;

FIG. 4 is a plan view of the device according to FIG. 3;

FIG. 5 is a side view of the guide device according to FIG. 2; and

FIG. 6 is a plan view of the guide device according to FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The applicator device 2 and guide device 3 shown in the drawings serveto apply adhesive to strip material, which can move relative to theapplicator device 2. Devices 2, 3 are used especially for the gluing ofso-called edge banding for furniture (furniture edge banding) whichconsists, for example, of flat, flexible plastic material, and is gluedto the external surfaces of furniture or parts of furniture. Of course,other substrates such as molding, packaging material, etc., could alsobe coated with adhesive in two dimensions with the same devices.

As FIGS. 1 to 4 show with particular clarity, an applicator head 2 has abase body 4 with an adhesive channel (not shown) in this base body 4. Asupport post 6 is used to support and position the applicator head 2permanently in a defined position. The support post 6 is provided at thebottom end with an attachment flange 8, through which holes 10 pass, sothat the post 6 can be screwed to a stationary structure (not shown).The applicator head 2 can be fastened to the support post 6 in anydesired position by a clamping device 12. For this purpose, a lockingscrew is tightened manually by a handle 14 so that a friction-lockingconnection is established between the locking device 12 and the supportpost 6, which connection can also be released again to allow adjustment.

On a section of the applicator head 2 (at the bottom in FIG. 1), thereis a nozzle assembly, which is designed as a slot nozzle 16, and isscrewed to the base body 4, so that adhesive can flow through theadhesive channel into the slot nozzle 16 and then be discharged througha slot with an elongated, slot-like exit opening 18. During operation,the strip material to be glued slides along a slide plate 19 in thedirection of the arrow 21 (FIG. 1), which illustrates the direction ofrelative motion.

In the applicator head 2, there is an applicator valve (not shown) forthe selective blocking or release of the flow of adhesive through theadhesive channel and thus through the exit opening 18. The applicatorvalve can be actuated pneumatically. For example, a needle valve can beused, in which a needle cooperates with a valve seat.

A sealing body (not shown) is mounted with freedom of movement in theslot of the slot nozzle 16 and seals off the slot laterally. The sealingbody is rigidly connected to a cylindrical piston, which moves axiallyinside one of the distribution channels. The sealing body extends fromthe piston to the exit opening 18 of the slot nozzle 16. By shifting thesealing body in the slot together with the piston in the distributionchannel, the length of the slot and thus the length of the exit opening18 can be varied.

By rotating a handwheel 20, which is connected to a threaded rod 24, thewidth of the slot and thus the width of the exit opening 18 can bevaried in the manner described above. By positioning the entireapplicator head 2 and thus the slot nozzle 16, it is possible to arriveat the exact position of the slot and of the exit opening 18 desired.

The guide device 3, illustrated seperately in FIGS. 2, 5, and 6, ismounted directly on the applicator head 2, or, more precisely, on thebase body 4 of the applicator head, by a swivel joint 26, so that theguide device 3 can be swiveled around a rotational axis 28 relative tothe applicator head 2. The swivel joint 26 has a bolt 30, which ismounted in a hole in the base body 4 as well as a lock nut 31.

The guide device 3 serves to conduct the strip material past the exitopening 18 of the slot nozzle 16 in a defined manner. The strip materialis first introduced through a slot 32, which is formed between twoplates 34, 36 a certain distance apart. Plates 34, 36 are connected toeach other by a connecting web 33. The strip material is conducted andguided through the slot 32 by a suitable conveying device (not shown).Alternatively, it would also be possible to provide only a single plateas a guide for the strip material in the feed area.

The guide device 3 has a first guide element 38, which is designed as arigid cylindrical bolt with a polished surface and which is essentiallyparallel to the exit opening 18. During operation, the first guideelement 38 is in its working position at a defined, adjustable distancefrom the exit opening of the slot nozzle (compare FIG. 3) and in contactwith a surface of the strip material, which is opposite the surface ofthe strip material to be glued. The guide element 38 fits into a holdingfixture 40 and can be removed or replaced by loosening the screw 42, sothat it can easily be cleaned.

Two additional edge-guide elements 46, 48, attached to a support 44 (seeFIG. 3) ensure during operation that the strip material is guidedlaterally, i.e., at the top and bottom in the example shown here, Withthese additional edge-guide elements 46, 48 contacting opposite edges orborders of the strip material. The support 44 is designed in the form ofa rod. Using screws 50, the distance of the guide elements 46, 48 fromeach other can be adjusted; that is, after screws 50 have been loosened,the edge-guide elements 46, 48 can be slid along the support 44 until inthe desired position, whereupon the screws 50 are tightened again. It istherefore possible to adapt the device to strip materials of differentwidths with a mechanism of very simple design. As a result of theguidance provided by the guide element 38 and additionally by theedge-guide elements 46, 48, the strip material to be glued is guidedreliably so that the glue can be applied uniformly in two dimensions.

The support 44 can also be moved in the vertical direction to arrive ata so-called production zero point by the use of an adjusting screw 52.

The guide device can be swiveled by means of a pneumatic cylinder 58around the rotational axis 28 of the swivel joint 26. A swivel support54 holds the holding fixture 40 and thus the first guide element 38 aswell as the additional edge-guide elements 46, 48 and their support 44.The pneumatic cylinder 58 can be actuated with pressurized gas suppliedthrough a compressed air line 60 in such a way that the support 54 isswiveled by a piston rod 62 away from the applicator head 2 and the basebody 4 and thus into the desired working position, so that the guideelement 38 is situated at the desired distance from the exit opening 18.

When the compressed air is turned off, the support 54 swings back into arest position as a result of the force of the spring integrated into thepneumatic cylinder 58, in which rest position the guide element 38 isfarther away from the exit opening 18 and the strip material is nolonger being conducted past the exit opening to receive a coating ofglue. The spring is thus a preloading device for exerting a preloadingforce on the swiveling guide device 3 and on the guide element 38 towarda rest position, in which the guide element 3 is held a certain distanceaway from the slot nozzle 16.

While the present invention has been illustrated by a description ofpreferred embodiments and while these embodiments have been described insome detail, it is not the intention of the Applicant to restrict or inany way limit the scope of the appended claims to such detail.Additional advantages and modifications will readily appear to thoseskilled in the art. The various features of the invention may be usedalone or in numerous combinations defending on the needs and preferencesof the user. This has been a description of the present invention, alongwith the preferred methods of practicing the present invention ascurrently known. However, the invention itself should only be defined bythe amended claims, wherein I claim:

What is claimed is:
 1. A dispensing device for applying adhesive onto amoving substrate having opposite first and second outer surfaces and anedge, comprising: an applicator head having a slot no opening andoperative to selectively block and release flow of the adhesive fromsaid slot opening of said slot nozzle onto the first outer surface ofthe moving substrate; and a guide device attached to said applicatorhead, said guide device including a first guide element configured tocontact the second outer surface of the moving substrate, and a secondguide element adapted to contact the edge of the moving substrate. 2.The dispensing device of claim 1, further comprising a swivel jointattaching said guide device to said applicator head.
 3. The dispensingdevice of claim 2, further comprising: a pneumatic cylinder operativelycoupled to said guide device to move said guide device about said swiveljoint, said first guide element being mounted in a distanced manner fromsaid swivel joint such that, when said guide device swivels, thedistance between said first guide element and said slot opening changes.4. The dispensing device of claim 1, further comprising: a preloadingdevice operative to exert a preloading force on said guide device towarda rest position in which said first guide element is distanced from saidslot nozzle.
 5. The dispensing device of claim 4, wherein saidpreloading device comprises a spring.
 6. The dispensing device of claim1, wherein said first guide element comprises a cylindrical bolt and isessentially parallel to said slot opening.
 7. The dispensing device ofclaim 1, further comprising a third guide element and a support, saidsecond and third guide elements being fixed to said support at avariable distance from each other.
 8. The dispensing device of claim 7,wherein said support is supported on said guide device so that saidsupport can be adjusted and held in a desired position.
 9. Thedispensing device of claim 1, wherein said guide device includes a guideslot formed by two spaced apart plates for receiving the movingsubstrate.
 10. The dispensing device of claim 1, wherein said guidedevice is removably attached to said applicator head.